Add "Most Common Implementation" row to high availablity table so the

table is less abstract.  Most common implementations were already
mentioned in the text.

doc/src/sgml/high-availability.sgml

-<!-- $PostgreSQL: pgsql/doc/src/sgml/high-availability.sgml,v 1.33 2008/11/17 18:55:14 momjian Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/high-availability.sgml,v 1.34 2008/11/19 04:46:37 momjian Exp $ -->
 
 <chapter id="high-availability">
  <title>High Availability, Load Balancing, and Replication</title>
@@ -287,6 +287,28 @@ protocol to make nodes agree on a serializable transactional order.
 
    <tbody>
 
+    <row>
+     <entry>Most Common Implementation</entry>
+     <entry align="center">NAS</entry>
+     <entry align="center">DRBD</entry>
+     <entry align="center">PITR</entry>
+     <entry align="center">Slony</entry>
+     <entry align="center">pgpool-II</entry>
+     <entry align="center">Bucardo</entry>
+     <entry align="center"></entry>
+    </row>
+
+    <row>
+     <entry>Communication Method</entry>
+     <entry align="center">shared disk</entry>
+     <entry align="center">disk blocks</entry>
+     <entry align="center">WAL</entry>
+     <entry align="center">table rows</entry>
+     <entry align="center">SQL</entry>
+     <entry align="center">table rows</entry>
+     <entry align="center">table rows and row locks</entry>
+    </row>
+
     <row>
      <entry>No special hardware required</entry>
      <entry align="center"></entry>
@@ -375,17 +397,6 @@ protocol to make nodes agree on a serializable transactional order.
      <entry align="center">&bull;</entry>
     </row>
 
-    <row>
-     <entry>Communication Method</entry>
-     <entry align="center">shared disk</entry>
-     <entry align="center">disk blocks</entry>
-     <entry align="center">WAL</entry>
-     <entry align="center">table rows</entry>
-     <entry align="center">SQL</entry>
-     <entry align="center">table rows</entry>
-     <entry align="center">table rows and row locks</entry>
-    </row>
-
    </tbody>
   </tgroup>
  </table>